Surface modification method of aramid, and reinforced natural rubber material and preparation method thereof

The invention discloses a surface modification method of aramid, a reinforced natural rubber material and a preparation method thereof. The surface modification method of aramid comprises the following steps of: dipping aramid fibre for 0.5-3h by using phosphoric acid solution at 20-50 DEG C, after cleaning and drying, dipping aramid fibre for 1-2h by using acetone solution of epoxy resin with the mass percentage concentration of 5-20% at normal temperature, and then modifying the surface of aramid after drying. According to the invention, active groups of surface modified aramid and terminated hydroxyl of epoxy resin and liquid rubber are chemically reacted simultaneously at mixing temperature, so that the interfacial bonding strength is improved; liquid rubber and matrix rubber are vulcanized together in the subsequent vulcanizing process of mixing rubber, so that a cross-linked network tightly combined with aramid fibre is formed; the problem that the matrix rubber in an original physical manner forms a self cross-linked network while being vulcanized is overcome, and therefore, negative phenomena of a rubber and aramid fibre interface can be reduced; and the aramid reinforced rubber composite material having good interfacial bonding and fibre dispersion can be formed.